Sulfonated



Mai

Patented Aug. 7, 1951 SULFONATED 3,7 -DIAMINODIBENZOTHIO- PHENE DIOXIDESMario Scalera, Somerville, and Dale R. Eberhart,

Middlesex, N. J assignors to American Cyanamid Company, New York, N. Y.,a corporation of Maine No Drawing. Application June 15, 1950, Serial No.168,392

7 Claims. 1

This invention is concerned with optical bleaching and brightening andespecially with new derivatives of benzothiophene distinguished by theirremarkable utility for this purpose. More specifically the inventionrealtes to water-soluble derivatives of acylated-3,7-diaminodibenzothiophene dioxides' and their use.

In particular, the invention utilizes a novel group of compounds whichare sulfonated derivatives of compounds containing the nucleus:

Xr- X:

R 0 NH- NH 0 0 R 02 I X4 X3 in which R and R are radicals of thealiphatic and aromatic series and X1, X2, X3, X4, X5 and X0 represent H,alkyl, alkoxy or halogen radicals, but at least one of said X1, X2, X3,X4, X5, and X5 being a hydrogen radical. As such, the presentapplication constitutes a continuation-inpart of our copendingapplication Serial No. 45,425, filed August 20, 1948.

It is well known that cellulosic materials tend to develop anundesirable yellowish cast with age. Unfortunately it cannot be removedby ordinary simple bleaching or scouring. Development of this yellownessis aggravated among other reasons, by continued exposure to light,weathering and repeated launderings. It is, therefore, particularlytroublesome in plastics and textile fabrics that must be subjected tothese conditions.

For many years, it has been the practice to attempt to conceal thisyellowing by the use of blue pigments or dyes, to neutralize thecomplementary yellow color of the cellulose. For this purpose,'the useof blue pigments, such as ultramarine or alkali blue, or of fugitiveblue dyestuffs, has become common practice in paper manufacture andlaundry operations.

While these blue coloring matters are often temporarily effective, theyare subject to serious disadvantages. For example, addition of a bluecolor to a yellow does not produce pure white, but rather a gray. Thegreater the intensity of the original yellow, the more bluing necessaryto hide it, and the darker in cast the resulting gray. Further, unlessan exact color balance is struck, the finished product is not even graybut may actually be blue.

In 1929, P. Krais (Mellianels Textilberichte, 1929-''pp. 468-9)suggested using not a, blue 2 coloring matter to absorb yellow light,but aesculin, a fluorescent substance capable of emitting blue light.Thus, the yellowing effect, which consists in absorbing the blue light,is truly destroyed by a substance which emits the blue light lost,resulting in true white instead of gray.

No widespread acceptance of this proposal occurred. This was largely dueto the lack of acceptable materials. To be suitable for this purpose, acompound should possess the properties of being:

1. Colorless in white light;

2. Strongly fluorescent under the influence oi ultra-violet rays such asare present in sunlight;

3. Fluorescing blue-white;

4. sufficiently substantive to be absorbed from very low concentrations;

5. Resistant to common agents such as soap. chlorine, and light;

6. Free from the tendency to decompose to colored products;

7 '7. Reasonably low in cost of production in proportion toeffectiveness;

8. Free from tendency to discolor soap or detergents when incorporatedtherein.

Aesculin, suggested by Krais, fails completely as to 4 and 5 and badlyas to 7. None of the available materials were suitable in all of theseproperties. It was particularly difficult to satisfy the third, fourth,fifth and eighth requirements.

It is, therefore, a principal object of the present invention to developnew compounds suitable for use as optical bleaching agents and combiningthe above-listed properties. This object has been found to beaccomplished, with an effectiveness both surprising and unpredictable,in the sulfonic acids of acylated 3,7-diaminodibenzothiophene dioxideand its nuclear substitution products. These compounds combine to anamazing degree the various desirable properties of affinity, highstrength, physical and chemical stability, substantivity, andfluorescent hue. Since current theories of substantivity andfluorescence are somewhat vague, the present invention is not restrictedto any particular theory of action.

The compounds herein disclosed will effectively neutralize theyellowness of cellulosic textiles even when applied from very minuteconcentrations. On the other hand, they can be applied from relativelyconcentrated solution when it is desired to produce greatly enhancedwhiteness and brilliance of discharge effects. The applica-. tion ofthese agents may be carried out in a separate rinse bath; or they may beused in conjunction with the soaping operations; or the agents Thecompounds of the present invention pos-.

sess a valuable property not shared with most other whitening agentswhich have been proposed in the art for similar purposes. They do notcause a discoloration of the detergent itself when mixed therewith.

Many brighteners of .other types, which are excellent in their whiteningeffect on the cloth to which they are eventually applied, neverthelesssuffer from the serious drawback of imparting a yellow discoloration tothe detergent with which they are admixed, even in the customarily smallamounts of .001 to 1% by weight. This is commercially very undesirable,and in fact detergents of pure white appearance are so stronglypreferred in the trade that certain auxiliary agents, such as methylumbelliferone, are often incorporated directly therein for the solepurpose of enhancing the whiteness of. the detergent itself.

It is therefore a particularly striking advantage of the brighteners ofthe present invention,

that they do not impair the whiteness of solid.

detergents. Actually in many cases they may enhance it in a mannersimilar to the above mentioned methyl umbelliferone; thus in effectcombining two separate and highly useful properties-whitening of thedetergent and whitening of the cloth-in a single compound.

Another notable advantage of these compounds over products used by theprior art for similar purposes is their superior chemical stability,particularly to chlorinebleaches. The importance of such property isquickly realized. when one considers that chlorine bleaching is anoperation almost universally associated with laundering or scouring.

These compounds also possess valuable properties other than as bleachingor whitening agents for white goods. For example, they may be used oncolored textiles to enhance the color effect of. many different dyes andpigments. Their mode of application for this purpose may vary: they maybe used in a preliminary treatment of the fabric, applied with the dye,or applied as an after treatment.

Utilization of the compounds of this invention is not limited totreatment of textile fabrics.

They may also be beneficially used in the manuiacture of paper and feltproducts and in making transparent or translucent sheets or pellicles ofcellulose or other origin. Their usefulness also extends to mutuallycompatible varnishes, plastic coatings and white or colored plasticshapes.

The compounds of the present invention may be prepared in a variety ofways. A sulfonated 3,7-diaminodibenzothiophene dioxide, and itssubstitution products such as the alkylated homologues and thehalogenated, nitrated and oxygenated derivatives may be acylated in thenormal manner with such acylating agents as acetic anhydride; fbutyrylchloride; trifluoroacetyl chloride; adipyl chloride; crotonyl chloride;ethoxyacetyl chloride; maleic anhydride; benzoyl and phenylacetylchloride and the alkyl, halo, nitro, amino, and oxygenated substitutionproducts thereof; the naphthoyl chlorides;

A difunctional acylating agent, such as phos-' gene, may be used to linktogether two molecules of benzidine sulfone. By the proper choice ofreagents and conditions, the 3- and 'l-nitrogens may be substituted bythe same or different acyl groups. Alternately, an unsulfonated,3,7-dlaminodibenzothiophene, dioxide and its above mentionedsubstitution products may be acylated with any of the acylating agentsmentioned above, and the resulting 3,7-diacylaminodibenzo thiophenedioxide may be sulfonated in a second step.

Thus it is evident that the sulfonic acid groups,

which are necessary for the practical fulfillment of the invention, maybe present in either the dibenzothiophene or the acyl nuclei, and thatthey may be introduced either before or after the acylation step. Thiswill be further illustrated in conjunction with several specificexamples given below.

The process of acylation before sulfonation is one of wideapplicability. For the acylation the best choice of reaction conditionsfor a given case is somewhat dependent on the reactivity and stabilityof the reactants. It has been found that it is generally convenient tocarry out the acylation of the unsulfonated diaminodibenzothiophenedioxide in an organic solvent at -150. The reaction is continued untilthe presence of primary amino groups is no longer detectable as, forexample, by diazotization with nitrous acid.

For the introduction of the sulfonlc groups following the acylationstep, the conventional method of sulfonation with sulfuric acid may beused. However, it is frequently advantageous to use chlorosulfonic acid,with or without a solvent. This provides a smooth method of conductingthe reaction, and tends to simplify the problem of isolating theproduct, which is obtained in high purity and good yield. For thisreaction, it has been found that nitrohydrocarbons, such asnitromethane, nitropropane, and nitrobenzene, are highly suitablesolvents; after completion of the reaction, the solvent is easilyremoved by steam distillation. It has been found possible, by operatingin a nitrohydrocarbon such as nitrobenzene, to first acylate the freedibenzothiophene dioxide diamine, and then to proceed immediately to thesulfonation with chlorosulfonic acid, without previous isolation. Theensuing sulfonation is advantageously conducted at room temperature orbelow. It is desirable to cool while the chlorosulfonic acid is added;frequently the sulfonation can then be completed around roomtemperature. When the sulfonation is finished, the reaction mixture isdrowned in ice and water, and the solvent removed by steam distillation.The product is isolated in good yield and purity, either as the freesulfonic acid or a salt thereof. The salts are of equal technicalimportance to the free acids and are understood to be their obviousequivalents.

In the case where it is desired to acylate after sulfonation, one maystart with an aminosulfonio 6 acid of the dibenzothiophene dioxideseries, ob The mixture is drowned in a mixture of ice and tainable forinstance by the processes of copend- 50 g. salt, filtered, the cakeneutralized and nitroing applications of Robert S. Long and Sien Moobenzene steamed 011, or the drowned mixture may Tsang, Serial No.168,379. filed June 15, 1950. be neutralized directly andsteam-stripped. and Sien Moo Tsang, Serial No. 184.707, filed 6 Afterfiltration, washing and drying,alight yellow September 13, 1950, bothassigned to the assignee product is obtained, soluble in water to a blueof the present application. With these amino fluorescent solution.

sulfonic acids, it is advantageous to perform the This product onhydrolysis regenerates unsuiacylation in an organic solvent with the aidof fonated 3,7-diaminodibenzothiophenedioxide and a tertiary amine or ofsubstituted guanidine, ac- 10 a sulionated benzoic acid, thus indicatingthat cording to the procedure of copending applicathe sulfonic acidgroups are introduced in the tions of Warren S. Foster and MarioScalera, acyl rings and not in the dibenzothiophene Serial No. 153,988,filed April 4, 1950, and Hans nucleus. The product is a very efi'ectivewhiten- Z. Lecher and Dale R. Eberhart, Serial No. 153,- ingagent,showing strong afiinity for vegetable 992, filed April 4, 1950,also assigned to the asfibers, and a bright bluish white fluorescence onsignee of the present application. such fibers. I

It has been observed that when it is desired Example 4 to produce asulfonated derivative of this class bearing the sulfonic groups in thedibenzothio- H088 SOaH phene dioxide ring, the process of sulfonationbe- I fore acylation, offers a sure way of obtaining the CONH S N OCdesired compound. The process of sulfonation following acylationgenerally produces sulfonated 0on1. Hb lo derivatives which carry thesulfonic group or groups in the outer acyl rings, provided, of course,3.7-diaminodibenzothiophenedioxide 2,8 disuch acyl rings are of thearomatic type, and casulfonic acid is dissolved in dilute sulfuric acidpable of sulfonation. Thus, by thetwo processes and treated withtriethylamine. The triethylhereinbefore described it is possible toprepare all amine salt crystallizes from the cold solution, and types ofproducts broadly disclosed in the present is filtered and dried. Aslurry of 30.4 parts of application. 1 the resulting salt in 133 partsof chlorobenzene The invention will be discussed more fully in and 30.3parts of triethylamine is heated under conjunction with the accompanyingexamples refiux with stirring and to it is added during about which arefurnished by way of illustration. Ex- 30 minutes 27.7 parts ofortho-ethoxybenzoi chlocept as otherwise noted all parts are parts byride. The reaction mixture is heated under reweight, and alltemperatures are in degrees flux for four hours and then treated with ancentigrade. additional portion of 30.3 parts of triethylamine ExampZeIand 27.7 parts of ortho-ethoxybenzoyi chloride.

HSO son: omo-O-corrn S NHCOOOCH;

Oz To 3 parts by weight of dry 3,7 -diaminodibenzo- Refluxing andstirring are continued overnight.

thiophene-5,5'-dioxide 2,8 disodium sulfonate The chlorobenzene andtriethylamine are reare added 7.7 parts of p-anisoyl chloride and /4moved by steam distillation after adding suiiicient to part of pyridine.The mixture is stirred and sodium carbonate to render the mixturealkaline heated to 150 -160 C., cooled, diluted with aceto brilliantyellow. The product is isolated in tone, filtered, washed, suspended inhot, dilute excellent yield in the usual manner by filtration, NazCOssolution, filtered, washed and dried to give washing with 2 brine anddrying.

a light brown product dissolving in water to a Example 5 strongly bluefluorescent solution. The product is valuablev for whitening ceilulosicand other ma- Ho's 08H terials.

Example 2 I 5 0 ONE S NH0 0 02 C H30- 0 CH:

If, in the procedure of the above example, the 0011, 011,0 anlsoylchloride is substituted by p-toluyl chloride, the di-p-toluyl derivativeis obtained'as a light A slurry of 122 parts of 3,7-diaminodibenzoyellow product. It has a similar shade of fiuoresnothiophenedioxide-2,8-disulfonic acid, 157 parts of cence. pyridine, and1110 parts of monochlorobenzene is Example 3 heated at reflux andtreated with a solution of 185 soan som cmoOcoma S nnooOoon. 0

To 12.3 parts of 3,7-diaminodibenzothiopheneparts of2,4-dimethoxybenzoyl chloride in 220 5,5'-dioxide in parts ofnitrobenzene are added parts of chlorobenzene. After three hours at re-20.4 parts of p-anisoyl chloride at; -150 C. flux, 250 parts of sodiumcarbonate are added, and The mixture is stirred at C. until primary themixture is steamed free of pyridine and amino groups can no longer bedetected, then chlorobenzene, salted with 5% its weight of soeooled and117 parts of chlorosulfonic acid added dium chloride, cooled to 15 C.and filtered. The during 30 minutes at l0-20 C. The mixture iscream-colored cake after washing with 2% brine stirred at 18-20 C. untilthe reaction is complete. 75 and drying at 90 C. represents an excellentyield CHaOOC 3,7-di-(2,4-dimethoxybenzoylamino) -dibenzothiophenedioxide-2,8-disodium sulfonate.

Example 6 H 0 3- --S 01H Example 7 H018 SOaH C ONE 8 NHO C-3,7-diaminodibenzothiophenedioxide-2,8-disulfonic acid is dissolved indilute sulfuric acid and treated with triethylamine. The triethylaminesalt crystallizes from the cold solution, and is filtered and dried.15.2 parts of the salt is slurried in 10 parts of pyridine and 110 partsof chlorobenzene. After heating to reflux, the mixture is graduallytreated with 20.2 parts of ophenyl-benzoyl chloride. Heating andstirring are continued until acylation is complete. The resultingslurryis made alkaline with aqueous sodium carbonate and steam distilled toremove the solvents. The product is then salted out with sodiumchloride, filtered, washed with brine, and dried.

Example 8 C 0 NH NH O C COOCH:

Example 9 H038 SOIH C|HaOCH2COHN S NHCOCHzOCuHI 0,

A mixture of 145 parts of chlorobenzene, 16 parts of pyridine, and 15.2parts of the triethylamine salt of3,7-diaminodibenzothiophenedioxide-2,8-disultonic acid is heated toreflux and gradually treated with 15.4 parts of phenoxyacetyl chloride.When acylation is complete the mixture is cooled, made alkaline withsodium carbonate, and subjected to steam distillation. The product issalted out in the usual way and filtered.

Example 10 H038 soan No-O o OHN- NHOCOCN A mixture of 16 parts ofpyridine, 145 parts of chlorobenzene, and 15.2 parts of thetriethylamine salt of 3,7-diaminodibenzothiophenedioxide-2,8-disulfonicacid is heated to reflux and gradually treated with 16.7 parts ofp-cyanobenzoyl chloride. After three hours of stirring and refluxing,the mixture is cooled, made alkaline with sodium carbonate solution, andsubjected to steam distillation. The bright yellow product is thensalted out with sodium chloride, filtered,

washed with brine, and dried. It is obtained in excellent yield.

Example 11 CH;CH=CHCOHN NHCQCH=CHCH| A mixture of 145 parts ofchlorobenzene, 16 parts of pyridine, and 15.2 parts of the triethylaminesalt of 3,7-diaminodibenzothiophenedioxide-2,8-disulfonic acid, isheated to reflux and treated gradually with 10.8 parts of crotonylchloride. The mixture is stirred and heated until acylation is complete,then made alkaline with sodium carbonate solution and steam distilled toremove the solvents. The addition of sodium chloride salts out theproduct as a bright yellow solid, which is filtered and dried.

1 Example 12 no; soul chasm-O0 OHN S NHocQsomm A mixture of 10.4 partsof pyridine, 83 parts of chlorobenzene, and 10.1 parts oi. thetriethylamine salt of 3,7-diaminodibenzothiophenedioxide-2,8-disulfonicacid is heated to reflux and treated with 15.9 parts ofo-carbomethoxybenzoyl chloride. When acylation is completed, the solidproduct is separated, dissolved in aqueous sodium carbonate and saltedout with sodium chloride. It is then filtered and dried.

A slurry of 7.6 parts of the triethylamine salt of3,7-diaminodibenzothiophenedioxide-2,8-disulfonic acid, in 10 parts ofpyridine, and 225 parts of chlorobenzene, is heated to and treatedslowly with 12.7 parts of p-phenylsulfonylbenzoyl chloride. Acylation iscompleted at reflux temperature, the mixture then being treated withaqueous sodium carbonate and steam distilled free of pyridine. Theyellow product is salted 2,668,493 a 9 out by the addition of sodiumchloride, filtered, manner, substituting l-naphthoic' acid for the 2-washed, and dried. naphthoic acid. Its properties are essentiallyExample 13 similar.

no. soirr crawl-Odom: S/ NHOCOBOiCH: O,

10.1 parts of the triethylamine salt of 3,7- 10diaminodibenzothiophenedioxide 2,8 disulionic acid is slurried in 275parts or chlorobenzene and HOJS- -so,rr parts of pyridine and heated toreflux. To this is gradually added 11.3 parts of p-methyli i H= HCOHN-S/ NHCOCH=CHC|H| sulionylbenzoyl chloride. When acylation is 15complete, the mixture is treated with aque A solution is prepared from26.3 parts of di-osodium carbonate and steam distilled free oftolylguanidine 1L9 parts of concentrated hydm pyndme' The yellow productis salted out with chloric acid, and water to the volume of 200 partschmride and filtered and driedof water. This is slowly added to asolution pre- Example 14 pared by adding 20.3 parts of3,7-diaminodibenzothiophened oxide 2,8-disulfonic acid to 100 partsH0is- SOIH of water, neutralizing with 5 N sodium hydroxide solution,and diluting to the volume or 200 parts omso -COHN S NH O 2 of water.The salt which crystallizes out is filtered, washed, and dried.

Example 18 A mixture of 24 parts of nitrobenzene and 4.4

parts of the above prepared di-o-tolylguanidine The procedure of thepreceding example is salt is heated to 120 and treated with 2.5 partslowed, using m-methylsulfonylbenzoyl chloride of cinnamoyl chloride. Themixture is then instead of the p'ismner' The product is similar heatedfurther to 140 to complete the reaction,

Example 15 cooled to 85, and treated with a solution of 1.9

parts of phenol in 5 parts of 5 N sodium hy- H03S droxide. The resultingbright yellow precipitate is filtered, washed with nitrobenzene andacetone 001m 8/ NHOC s and dried.

a Example 19 H035 soda 0 OHN 8 NH0 0 CH; CH:

15.2 parts of p-anisic acid is added gradually to 58 parts ofchlorosulfonic acid at 511 C.

A mixture of 15.2 parts of the triethylamine salt, prepared as describedabove, 150 parts of chlorobenzene, and 15.8 parts of pyridine is stirredand refluxed and gradually treated with warmed to 75 and maintained atthis tempera- 13.2 parts thiophene-2-carboxylic acid chloride. ture onehour. It is then cooled, drowned in ice, After stirring and refluxingfor three hours the and filtered. 10 parts of the resulting sulfonylmixture is worked up in the usual manner, givchloride is treated with 8parts of morp olineing a product of pale yellow color. The reactionmixture is slowly treated with 5 N a sodium hydroxide, the temperaturerising to 25. After acidification with hydrochloric acid, the p-anisicacid m-sulfon morpholide is filtered. It melts at 218-9.

Example 16 I usual manner. This is then added to a mixture of 12 partsof nitrobenzene and 2.2 parts of the di-o-tolyguanidine salt prepared asin Example at scribed in the above exam P188, is stirred and 15 treatedwith a solution of 0 .9 part of phenol in fluxed whilebeing treated with17.2 parts of 2 5 N 50am! 9 i immediate Z-naphthoylchloride dissolved in22 parts of mm .mmatwn P a yenw preclplta'ie' The Pmdmt zene. Thepyridine is removed by steam distillag g gi mtmbenzene tion inthepresence of aqueous sodium carbonate, o owe y ace an r e and the paleyellow product isolated in the usual Emmple 20 er, The analogousdisulfonanilide, which has sim- Example 17 ila'r properties, is obtainedin a similar way, substituting aniline for morpholine in the above Thel-naphthoyi isomer is prepared in the same 75 procedure.

After one-half hour the mixture is gradually HOaS- 303B .6 parts of thisproduct is converted to the COHN NHOC- corresponding carboxylic acidchloride by treat- 8 ment with 1.6 parts of thionyl chloride, in theExample 21 COHN NHOC OCHa CH240 H: SOaH CH3 4 CE:

3.6 parts of 2,4-dimethoxybenzoic acid is converted to acid chloride bytreatment in the usual way with 2.6 parts of thionyl chloride in thepresence of 8 parts of pyridine. This is added at 30 to a solution of2.0 parts of 3,7-diaminodibenzothiophenedioxide in 49 parts of pyridine.The product precipitates out and is filtered, washed with alcohol andwater, and dried. Sulfonation is effected by adding 2.7 parts of theresulting product to 11-12 parts of chlorosulfonic acid at minus 8 to 0C. and stirring for one and one-half hours at a maximum temperature of15. The mixture is then drowned in ice and filtered and washed. Theproduct is slurried in water, neutralized with sodium hydroxidesolution, filtered, and dried at 110.

Example 22 A paste is prepared from 5000 parts of water and 10,000 partsof a commercial detergent powder, containing as its active ingredientapproximately 35% on a dry weight basis, of a sodium alkylarylsulionate,combined with major proportions of sodium tripolyphosphate and sodiumsulfate, and minor amounts of sodium silicate and sodium chloride. Thispaste is heated on a water bath and into it is stirred 6 parts of the3,7-dianisoylaminodibenzothiophenedioxide-2,8-disodium sulfonate,prepared as in Example 1, followed by an additional 5000 parts of hotwater. When mixing is complete the paste is dried at 90 C. to a powder,which is conditioned for twenty-four hours at and a relative humidity of88%. obtained, which has a moisture content of 510%, and a brightenercontent of .06% on a dry weight basis, corresponds in composition tocommercial detergent-brightener products, and effectively restores whiteshades when used to launder cotton goods which are yellow with age.tergent product itself is pure white in color, being unaflected inappearance by the presence of the brightener substance.

Example 25 1 SOIH OCH:

To 6'77 parts of oleum is gradually added 4 105.3 parts of3,3'-dichlorobenzidine sulfate, the

HOaEO-NHCOHNQIj-NHCOHNOSQH A mixture of 2.5 parts of3,7-diaminodibenzothiophenedioxide and 5.7 parts of phenyl isocyanate isheated at 125-30 until reaction is Example 23 E000 H0. SOaH coon COHNNBC 0- A mixture of 3 parts of phthalic anhydride and 1.1 parts of thedi-o-tolylguanidine salt, prepared as in Example 18, is fused to amaximum temperature of 220. The .mixture is cooled to and treated with asmall quantity of nitrobenzene followed by 6 parts of 10 N sodiumhydroxide and 6 parts of alcohol to precipitate the yellow solidproduct, which is dried at 110.

Example 24 An illustration of the incorporation of compounds of thisinvention in detergents is the following:

temperature being maintained below 20. The mixture is heated to C. andmaintained at this temperature three hours. It is then drowned in 1500parts of ice and water. The precipitate is thoroughly washed, and thendried at 75 C. This is the dichlorodiamino dibenzothiophene dioxide ofthe probable formula:

c1 Cl NH: NH: s 02 the positionof the sulfone bridge not being clearlyestablished.

Acylation is carried out as follows: To a stirred suspension of 15.8parts of the above prepared compound in 147 parts of pyridine, there isgradually added 34.5 parts of anisoyl chloride. The resulting mixture isthen refluxed until acylation is complete, as shown by the disappearanceof primary amine groups. The reaction mixture is drowned in 200 parts ofwater containing 20 parts of sodium carbonate, and filtered. The cake isthoroughly washed and dried at 75 C.

Sulfonation is carried out by forming a suspension of 16.1 parts of theabove prepared compound in parts of nitrobenzene and gradually treatingwith 5.9 parts of chlorosulfonic acid. The mixture is stirred forone-half hour at about 35 C. and then heated to 120 C. and kept at thistemperature for one-half hour. The product is isolated by drowning inethanol, filtering, and washing. It is a light-straw color powder,soluble in water, and having marked sub- The product thus The de-2,568,498 13 14 siantivity for cellulosic fibers, to which it imparts abright blue fluorescence under ultraviolet light.

Example 26 6.9 parts of anisoyl chloride. The reaction mixture isdrowned in 100 parts of water, made alkaline with sodium carbonatesolution, and the product filtered, washed, and dried. When 93.0 partsof tolidine sulfate is gradually added to 677.5 parts of oleum, thetemperature being kept below C. The mixture is then heated to C. over aone hour period, stirred Example 28 -.:-SOJH cnloOcomi- 41110000011;

at this temperature for 3 hours, then heated 20 A mixture of 28.2 partsof benzidine sulfate to 120 C., kept at this temperature 2 /2 hours, and211.2 parts of 26.8% oleum is heated at 70 and finally heated forone-half hour at 140 C. C. for 2 hours, cooled to about 40 C., andtreated The reaction mixture is drowned in 2000 parts with 46.0 parts of86.3% sulfuric acid. The mixof water. The yellow disulfonic acid isfiltered, ture is then heated to about 140 C., stirred at washed, anddried. This intermediate has the 26 this temperature for about 18 hours,and finally probable formula: for 2 hours at about 180 C. The reactedmixture is drowned in 1,000 parts of water, cooled.

and filtered. The filter cake is slurried in 500 treated with an aqueoussolution of this product, cotton cloth acquires an intense greenish-bluefluorescence under ultraviolet light.

parts of water, neutralized to a pH of 'l by the NH N n addition oftriethylamine, and filtered. On so H 0, 6 acidification with 5 Nsulfuric acid, the 3,7-diaminodibenzothiophenedioxide 2 sulfonic acidThe exact location of all the substituents has separates from SolutionThe resulting mixture not bee determinedis filtered at the boil, and theproduct washed 21.7 parts of the drsulfonic acid sci-prepared 3b withwater and dried is dissolved i 1 Parts Of dry Pyridine treated A mixtureof 12.8 parts of the above prepared with 26.0 parts of anisoyl chloride,and refluxed product, 110 parts f chlorobenzene, 5. parts of for 3hours. The mixture is then steam distilled pyridine, and 31 parts fanisoyl chloride is in the presence of sodium carbonate, to removefluxed for 24 hours, or until cylation is pyridine. The light coloredprecipitate remaining 0 m t as shown by t disappearance f priisfiltered, washed with 5% sodium chloride solumary mino groups. Thereaction mixture is tion followed by i Water, and driedthen freed ofpyridine and chlorobenzene by Example 27 steam distillation in thepresence of sodium car- CH3O- -0CH: omo-O-conn NHCOGOCH:

scan a 244 parts of dianisidine is slurried in 315 parts bonate. Theproduct is salted out with sodium of glacial acetic acid and graduallytreated with h r de, washed with 2% br ne, and dried at 236 parts ofacetic anhydride. Acetylation is An excellent yield of a pa Coloredcompleted by refluxing, the mixture being cooled solid is obtained. Theproduct is sp rin l $01u and filtered. The product, diacetyldianisidine, ble in Water, and S even from very dilute melts at about243 C. after being washed with solutions, a marked aflinity forcellulosic fibers, l h l, 55 to which it imparts a bright bluish-whitefluores- 323 parts of t above prepared diacetyl 1- cence underultraviolet irradiation. anisidine is gradually dissolved in 330 partsof Example 29 nso soin 01130000101 8 -Nrro0Ooom 35% oleum at 15-30 C.The solution is slowly A mixture of 14.1 parts of benzidine sulfateheated to 60 C. and stirred at this temperature and 113 parts of 25%oleum is heated at C. for three hours. The resulting dark red solufortwo hours, then rapidly heated to 140 C. tion is drowned in 1600 partsof ice and water. and maintained at this temperature for 3 hours. Theresulting solution is heated to 100 C. It is then drowned in 600 partsof ice, followed for one hour, cooled to room temperature, and 7 by 10.1parts of triethylamine and 500 parts of filtered. The yellow product iswashed with water. The solution is cooled and filtered to ethanol anddried. remove the triethylamine salt of the disulfonic Acylation iseffected by heating at C. for acid. The filtrate is than evaporated to138 one hour a mixture of 5.1 parts of the above parts and the separatedsolid filtered and disprepared compound, 29.3 parts of pyridine, and IIsolved in 100 parts of water containing excess H803 SOa NHi isrecrystallized from water.

To a stirred refluxing slurry of 5.6 parts of the above preparedtriethylamine salt, 77 parts of chlorobenzene, and 6.7 parts ofpyridine, is gradually added 6.9 parts of anisoyl chloride. Stirring andrefluxing are continued until acylation is complete. The mixture is thenfreed of solvents by steam distillation in the presence of sodiumcarbonate, and the cream-yellow product salted out of solution by theaddition of sodium chloride.

Example 30 B80 HS 03 or-CwHfllONH S Nncocmm-a 14.6 parts of3,7-diaminodibenzothiophene- 2,8-disuli'onic acid triethylamine salt isadded to 17.2 parts of mixed on and B naphthoyl chloride in 49 parts ofdry pyridine. The mixture is heated at reflux for a half hour, dilutedwith 100 parts of water containing 20 parts of soda ash and 20 parts ofsalt and steamed free of pyridine. The solidis filtered oil and washedwith dilute brine and finally ice water. There A mixture of 8.6 partsoithe above-prepared compound, 80 parts of pyridine, and 6.9 parts ofp-anisoyl chloride is refluxed until acylation is complete. Thereactionmixture is then drowned in a solution of sodium chloride andsodium carbonate, containing enough ice to keep the temperature in therange 10 to 15 C. The light yellow product is filtered, washed withbrine, and dried at 75 C. It imparts fluorescence to cotton cloth.

We claim: I

1. A sulfonated dibenzothiophene dioxide selected from the group ofsulionic acids and sulionates of the formula 11-0 OHN NHC O-R whereinRCO- and R'CO are carboxylic acyl radicals and X1, X2, X3, X4, X5, andX8 are selected from the group consisting of the H, sulfonic, halogen,lower alkyl and lower alkoxy radicals, at least one of R and Rcontaining a sulfonic radical when none of the X's are sulionicradicals.

2. A sulfonated dibenzothiophene dioxide according to claim 1 in whichthe'carboxylic acyl radicals are of aromatic carboxylic acids.

3. A compound according to claim 2 in which at least one of thecarboxylic acyl radicals contains a sulfonate substituent.

4. A compound according to claim 2 in which the dibenzothiophene nucleuscontains at least one SOaH substituent.

5. A compound of the formula 01130 no, son: OCH: omoG-corm \s NHCO O cmresults an excellent yield of product.

Example 31 CEO OCH;

66 parts of 'diacetyl dianisidine (as prepared in Example 27) isgradually added to 660 parts of 35% oleum, then slowly heated to 60 0.,kept at this temperature three hours, and drowned in 3000 parts of iceand water. After one hour at 15 C., a colorless precipitate forms, whichis filtered out. Higher temperatures should be avoided to preventhydrolysis of the monoacetyl group. The product is filtered and washedwith ethanol followed by benzene. It is dried at 75 C.

CH O O CH:

CHaCONH NH:

and its salts. 6. A compound of the formula H0:S soan COHN NHCO CHaOONHs NHCOGO CH; 8

2 S all and its salts.

7. A compound of the formula HaCO HO S- soan 0cm ECO-com: NHCOGCH:

and its salts. I

MARIO SCALERA. DALE R. EBE'RHAR'I'.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

1. A SULFONATED DIBENZOTHIOPHENE DIOXIDE SELECTED FROM THE GROUP OFSULFONIC ACIDS AND SULFONATES OF THE FORMULA